A timestamp is an indication of when an event occurred. In computer systems, often a timestamp refers to Unix time, or the number of seconds since midnight Jan. 1, 1970 in coordinated universal time. A Unix time reference can be used to give a date and time in many different forms as well as to calculate an elapsed time between timestamps. The standard Unix timestamp is a signed integer data type and traditionally 32 bits. Being an integer data type means that the timestamp has a resolution of one second. In a signed integer 32 bit timestamp, a range of about 136 years in total is covered. The minimum representable time is 1901-12-13T20:45:52Z, and the maximum representable time is 2038-01-19T03:14:07Z.